Communication apparatus and wireless communication system

Abstract

A communication apparatus constitutes a wireless communication system with a base station and a terminal station, and relays and transfers a signal transmitted and received between the base station and the terminal station. The communication apparatus uses a frequency different from that at a time of reception to amplify and transfer the received signal, when having received a signal transmitted from the base station or the terminal station.

1 . A communication apparatus that constitutes a wireless communication system with a base station and a terminal station, and relays and transfers a signal transmitted and received between the base station and the terminal station, wherein
 when having received a signal transmitted from the base station or the terminal station, the communication apparatus uses a frequency different from that at a time of reception to amplify and transfer the received signal.   
     
     
         2 . The communication apparatus according to  claim 1 , wherein the communication apparatus corresponds to multicarrier communication, and performs transfer processing, designating a continuous predetermined number of subcarriers as one processing target. 
     
     
         3 . A wireless communication system constituted by a base station, a terminal station, and a relay apparatus that relays and transfers a signal transmitted and received between the base station and the terminal station, wherein
 when having received a signal transmitted from a first communication apparatus, which is the terminal station or the base station, the relay apparatus amplifies the received signal and transfers the amplified signal to a second communication apparatus, which is a destination thereof.   
     
     
         4 . The wireless communication system according to  claim 3 , comprising the relay apparatus in plural, wherein
 the respective relay apparatuses sequentially receive signals continuously transmitted from the first communication apparatus with a specific frequency in each time slot, and transfer the signals in a time slot after a predetermined time period, based on a time slot in which the signals are received.   
     
     
         5 . The wireless communication system according to  claim 4 , wherein the respective relay apparatuses transfer the signals in a time slot subsequent to a time slot in which the signals are received. 
     
     
         6 . The wireless communication system according to  claim 4 , wherein the respective relay apparatuses use a common transmission frequency in the signal transfer processing. 
     
     
         7 . The wireless communication system according to  claim 4 , wherein the respective relay apparatuses use a transmission frequency different from each other in the signal transfer processing. 
     
     
         8 . The wireless communication system according to  claim 3 , comprising the relay apparatus in plural, wherein
 the first communication apparatus continuously transmits signals to the second communication apparatus,   a first relay apparatus among the relay apparatuses transfers a signal transmitted from the first communication apparatus in a first time slot, which is a predetermined time slot, in a second time slot, which is a time slot subsequent to the first time slot, and   a second relay apparatus different from the first relay apparatus among the relay apparatuses transfers a signal, which is transmitted from the first communication apparatus in the second time slot, in a time slot subsequent to the second time slot.   
     
     
         9 . The wireless communication system according to  claim 8 , comprising at least one of the first relay apparatus and the second relay apparatus in plural. 
     
     
         10 . The wireless communication system according to  claim 4 , wherein
 in a transfer operation performed by simultaneously using a plurality of relay apparatuses, an allocation pattern of a frequency used by the respective relay apparatuses is defined beforehand, and the respective relay apparatuses and a base station hold the allocation pattern,   when a usable frequency is allocated to the respective relay apparatuses, the base station informs the respective relay apparatuses of a frequency allocation result with respect to a specific relay apparatus, and   the relay apparatuses other than the specific relay apparatus among the respective relay apparatuses specify a frequency allocated to themselves based on the frequency allocation result with respect to the specific relay apparatus.   
     
     
         11 . The wireless communication system according to  claim 10 , wherein
 when the base station is provided in plural,   a different frequency allocation pattern is applied to each cell managed by each of the base stations.   
     
     
         12 . The wireless communication system according to  claim 3 , wherein
 the relay apparatus includes a plurality of antennas, and   the relay apparatus sequentially receives signals continuously transmitted from the first communication apparatus with a specific frequency in each time slot by using the respective antennas, and transfers the signals in a time slot after a predetermined time period, based on a time slot in which the signals are received.   
     
     
         13 . The wireless communication system according to  claim 12 , wherein the relay apparatus transfers the signals in a time slot subsequent to a time slot in which the signals are received. 
     
     
         14 . The wireless communication system according to  claim 12 , wherein the relay apparatus uses a common transmission frequency by the respective antennas. 
     
     
         15 . The wireless communication system according to  claim 12 , wherein the relay apparatus uses a transmission frequency different from each other by the respective antennas. 
     
     
         16 . The wireless communication system according to  claim 3 , wherein
 the relay apparatus includes a plurality of antennas,   the first communication apparatus continuously transmits signals to the second communication apparatus, and   the relay apparatus uses a first antenna among the antennas to transfer a signal transmitted in a first time slot, which is a predetermined time slot, from the first communication apparatus in a second time slot, which is a time slot subsequent to the first time slot, and uses a second antenna different from the first antenna among the antennas to transfer a signal transmitted in the second time slot from the first communication apparatus in a time slot subsequent to the second time slot.   
     
     
         17 . The wireless communication system according to  claim 16 , comprising at least one of the first antenna and the second antenna in plural. 
     
     
         18 . The wireless communication system according to  claim 12 , wherein
 in a transfer operation performed by simultaneously using the antennas included in the relay apparatus, an allocation pattern of a frequency used by the respective antennas is defined beforehand, and the relay apparatus and the base station hold the allocation pattern,   when a usable frequency is allocated to the relay apparatus, the base station informs the relay apparatus of a frequency allocation result with respect to a specific antenna, and   the relay apparatus specifies a frequency allocated to other antennas based on the frequency allocation result with respect to the specific antenna.   
     
     
         19 . The wireless communication system according to  claim 18 , wherein
 when the base station is provided in plural,   a different frequency allocation pattern is applied to each cell managed by each of the base stations.   
     
     
         20 . The wireless communication system according to  claim 3 , wherein
 the first communication apparatus multiplexes a plurality of signals including a known signal component by using a same frequency in a same time slot,   the relay apparatus transfers a received signal from the first communication apparatus to the second communication apparatus, and   the second communication apparatus separates respective multiplexed signals based on a known signal component included in the received signal from the relay apparatus.   
     
     
         21 . The wireless communication system according to  claim 3 , wherein
 the first communication apparatus transmits a plurality of signals including a known signal component by using a different frequency in a same time slot,   the relay apparatus synthesizes respective signals received from the first communication apparatus and transmits an acquired multiplexed signal to the second communication apparatus, and   the second communication apparatus separates respective multiplexed signals based on a known signal component included in the received signal from the relay apparatus.   
     
     
         22 . The wireless communication system according to  claim 3 , wherein
 a band including a first frequency band to be exclusively used by the first communication apparatus and a second frequency band to be exclusively used by the relay apparatus is designated as a system band, and   the base station individually manages the first frequency band and the second frequency band.   
     
     
         23 . The wireless communication system according to  claim 22 , wherein
 when the base station is provided in plural,   a repetitive pattern of a usable frequency allocated to each cell is set to be a pattern different between the first frequency band and the second frequency band.   
     
     
         24 . The wireless communication system according to  claim 22 , wherein a usage frequency of a same frequency in a repetitive pattern of a usable frequency to be applied to the second frequency band is set higher than that of a same frequency in a repetitive pattern to be applied to the first frequency band. 
     
     
         25 . The wireless communication system according to  claim 3 , wherein
 when the terminal station is provided in plural,   the base station selects a terminal station to which a transmission permission is given in each time slot from the terminal stations, and   in a scheduling process at a time of selecting the terminal station to which a transmission permission is given,   each of the terminal stations transmits a sounding signal orthogonal to each other with a same frequency in a same time slot,   the relay apparatus transfers the sounding signal to the base station, and   the base station performs selection of the terminal station to which a transmission permission is given and allocation of wireless resources to a selected terminal station, based on the sounding signal transferred by the relay apparatus.   
     
     
         26 . The wireless communication system according to  claim 25 , wherein the base station selects the terminal station to which a transmission permission is given based on a reception SINR of the sounding signal, and determines an MCS to be used at a time of transmission by the selected terminal station based on the reception SINR of the sounding signal transmitted by the terminal station. 
     
     
         27 . The wireless communication system according to  claim 26 , wherein the base station selects terminal stations in a number, with which a system throughput becomes maximum, as terminal stations to which a transmission permission is given, sequentially from a terminal station having a largest reception SINR of the sounding signal. 
     
     
         28 . The wireless communication system according to  claim 25 , wherein
 when the relay apparatus is provided in plural,   each of the relay apparatuses transfers received sounding signals from the respective terminal stations in a same time slot by using a frequency different from each other.   
     
     
         29 . The wireless communication system according to  claim 25 , wherein
 when the relay apparatus includes a plurality of antennas,   the relay apparatus transfers received sounding signals from the respective terminal stations by the respective antennas, in a same time slot by using a frequency different from each other.   
     
     
         30 . The wireless communication system according to  claim 3 , wherein
 the relay apparatus uses a gain instructed from the base station in the signal transfer process, and   in a process in which the base station controls the gain to be used in the signal transfer process by the relay apparatus,   the relay apparatus amplifies a noise component included in the relay apparatus or a known component with a gain according to an instruction from the base station, and transmits an acquired amplified signal to the base station, and   the base station determines a gain to be informed to the relay apparatus next time based on a reception SINR of the amplified signal transmitted from the relay apparatus.